This invention generally relates to a wet well pumping system and, more particularly, to a method of installing and servicing the system for maintenance and replacement.
Wet well pumping systems for pumping waste water such as sewage, including liquid and solid waste, from community structures, such as domestic residences, office buildings, companies, industries, farms, institutions, and the like, to sewage or drainage pipes for treatment in a sewage treatment plant prior to safe, sanitary discharge, are well known. The sewage is typically collected in a wet well, which may be below or above ground. In a typical multi-story, office building application, the wet well is located below street level in the basement of the building and collects sewage from each floor, and the pumping system pumps the collected sewage back up to a street sewage pipe at a higher elevation. A typical pumping system includes one or more submersible pumps in the wet well and connected to one or more runs of discharge pipes that include elbows for changing direction from the horizontal to the vertical, as well as risers for changing elevation. The risers extend generally upwardly from inside the well, through a cover overlying the well, and outside the well to the street sewage pipe. Valves in the risers resist back flow of the sewage toward the pumps.
A new installation of such a wet well pumping system is often problematic, because the system is installed from the “bottom up” and is customized for each location. Typically, the well is fabricated with studs permanently anchored in the well floor. For example, in the case of a concrete-poured well, threaded studs extend upwardly from the poured concrete, and the pumps and the elbows are initially lowered into the well and bolted directly to the anchored studs. Then, the risers are connected to the elbows, and the risers are passed through clearance holes in the cover. Oftentimes, the risers are not properly aligned with these clearance holes. To achieve alignment, sometimes the clearance holes are enlarged on the job site. Sometimes, the pumps and/or the elbows have to be unbolted from the floor and jockeyed to new positions. Sometimes, the floor is not level at these new positions, thereby requiring further jockeying of the various system components until everything is more or less aligned. A custom installation is therefore both laborious and time consuming.
Servicing an installation of such a wet well pumping system is also often problematic. Removal and replacement or repair of broken or malfunctioning submersible pumps in the pumping system is time consuming, often requiring several personnel and exposing these personnel to possible unsafe conditions due to the possible accumulation of poisonous gases within the well. The service personnel are also exposed to possible environmental hazards from the wet and slick environment and the confined space within the well, as well as from possible electrical hazards associated with the connection of electrical wiring to the pumps from an electrical system. Furthermore, especially with the passage of time, inevitable corrosion between the pipes and the pumps cause them to fuse to each other and, as a consequence, the service personnel often have to break at least some of the pipes and/or bolts in order to service or replace a malfunctioning or broken pump.